The supply of water to be vaporized in steam generating apparatuses may be provided by a water reservoir, thus allowing for a limited autonomy in certain household appliances. The water stored for an operation cycle is heated by heating means in a boiler. The generated steam can be applied without the need of the steam generating apparatus being coupled permanently to a permanent water supply, e.g. a water conduit. In consequence, the steam generating apparatus, i.e. its water reservoir, has to be refilled regularly. Therefore, a water-filling opening for (re-) filling the boiler manually after each operation cycle is provided. The water-filling inlet commonly is cup-shaped to allow for easy refilling by the user and may be closed/opened by a cap. Usually the boiler forms the water reservoir or is directly coupled to it. Thus, the boiler is pressurized by the steam pressure. In addition to the water-filling opening a draining opening may be provided for draining off water and debris from the boiler. A further possibility is using one single opening for filling and draining purposes.
Besides the mentioned limited systems, unlimited systems are known. In these systems the boiler is permanently connected to an unlimited water supply and the boiler is generally provided with a dedicated draining opening.
These designs raise a number of disadvantages and hazards for the user: Refilling or cleaning the boiler after waiting for the boiler to cool down is time consuming. Opening the boiler with steam pressure present inside the boiler forces steam outside while opening the cap. This hot steam endangers the user. Further, water being poured into the boiler during refilling may be vaporized instantaneously due to heat surfaces inside the boiler (e.g. boiler shell, heating plate). This undesirably generated steam escapes through the opening in the boiler. Typically the user wants to minimize the time needed for refilling the boiler and tries to pour as much water per time as possible by filling the cup-shaped water inlet. In these situations he frequently experiences water splashing out of the boiler opening.
It is an object of the invention to provide an apparatus and a method of operating a steam generating apparatus having improved water-refilling and draining capabilities.